PIL are living in a property we own as due to poor finances do not have their own place. Both currently not working but looking for jobs. They've asked DH to pay the council tax this month as they are short. They are not ones to cut their cloth and I could see this coming (they used to borrow from DH more regularly and usually repaid although he often picked up bill for family events).
We both work FT and put all income into family pot and from that have monthly allowance for personal spending. He assumed he'd help PIL from his personal spends but now seems annoyed I didn't offer for it to come out of the family pot. He can afford what they are asking for (about half his monthly discretionary spending).
From my POV, although we are financially comfortable now we cannot afford to support PIL long term beyond living in our property rent free. They have not saved to retire and cannot live the life they want to on their small pensions. DH is understandably stressed by this as it falls to him to pick up the pieces although he will never get clear information from his parents about their need for regular support or speaking to them to reduce their expectations of what is achievable on their budget.
My AIBU is that I don't feel that our family money should support them, if DH wants/needs to help with bills it should come from his own money as it might help him address with them their situation. I admit my judgement might be clouded as I have a different situation with my own parents and have had issues with being on the same page with PIL in the past.
YABU - you should help PIL from the family pot
YANBU - DH should use his own money when they need help